Ropes of various types are normally distributed on spools which allow the purchaser to mount the spool and dispense the rope simply by pulling the rope to cause the spool to rotate. The rope on the spool is sufficiently long to provide a supply of rope for cutting to length as required, until the spool is used up.
Modern ropes made from synthetic plastics material are commonly thermoplastic. The user can fuse the end of the rope using a heating instrument of some kind. Commonly, the user will cut the rope after binding the location of the cut using a tape so that after cutting through the tape the end of the rope remains tight. The tape is left in place and then heat is applied to fuse the rope at the end. This prevents unravelling in use and separation of layers in the case of ropes that are multi-layered.
Although there is no difficulty with this process when rope is used occasionally, it is very labour intensive when used by manufacturers of products requiring a great number of preselected lengths of rope.
Because of these difficulties, various machines have been suggested for cutting rope to length. An example of such a machine is found in U.S. Pat. No. 4,332,637 to Miller. This patent issued in 1982 and illustrates a machine which measures rope, positions the rope for cutting, heats the rope locally using heated air to fuse a portion of the rope, and then a knife severs the rope through the heated portion. The cutting action is necessary because the relatively cold blade must be forced through the rope.
While the U.S. Pat. No. 4,332,637 demonstrates improvements over the prior art, it suffers from major disadvantages. First of all, air is not a good medium to apply heat to a rope because of the time it takes to transfer sufficient heat to fuse the rope. This delay can be significant, particularly in production machinery where speed is important. Secondly, the machine requires tuning so that the fusing of the rope takes place before the blade is used to sever it. Clearly, it would be difficult to ensure that the blade is used at just the right moment. Since the rope will vary in quality, this timing may require significant testing with the result being that some of the rope could be wasted. Also, the heat must be just sufficient to fuse the rope without actually melting it. The blade will tend to cool the rope and will require sufficient load to cut the rope.
The present invention is intended to overcome the disadvantages in the art and in particular disadvantages demonstrated in U.S. Pat. No. 4,332,637. In particular, the invention provides apparatus which uses heat to fuse and sever the rope contemporaneously to provide a more efficient operation.